Optical device



FIG. 1 is a front, left perspective view of an optical device, showing our new design;

FIG. 2 is a rear, right perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof;

FIG. 7 is a top plan view thereof; and,

FIG. 8 is a bottom plan view thereof.

The broken lines in the drawings depict portions of the optical device that form no part of the claimed design. 

CLAIM The ornamental design for an optical device, as shown and described. 